At places where food is handled, such as food factories, kitchens in restaurants and processing workshops in grocery stores, disinfection of floors, walls, tools, facilities and the like is required. Various germicides have been hitherto used such as alcohols, chlorinated compounds, peroxides, cationic surfactants, amphoteric surfactants and biguanide compounds. For example, didecyl dimethyl ammonium chloride and polyhexamethylene biguanide hydrochloride are safe and effective germicides and are frequently used.
Microorganisms resistant to quaternary ammonium salts and biguanide germicides (hereinafter also referred to as “drug-resistant microorganisms”) have been developed in the course of repeated use of these germicides and cause insufficient disinfection. For example, as described in Non-Patent Document 1, bacteria of genus Pseudomonas and genus Serratia are known as microorganisms resistant to didecyl dimethyl ammonium chloride and polyhexamethylene biguanide hydrochloride. Although the types of germicides used for the disinfection may periodically be changed in order to prevent the development of drug-resistance in microorganisms, frequent change of germicides causes low working efficiency and high costs. Drug-resistant microorganisms are usually treated by chlorinated germicides such as sodium hypochlorite. The chlorinated germicides, however, cause corrosion and damages on facilities and devices, and also cause unfavorable residual odor. Sliminess is prone to remain after using didecyl dimethyl ammonium chloride. Stickiness is prone to remain after using polyhexamethylene biguanide hydrochloride.
Germicides comprising didecyl dimethyl ammonium chloride and polyhexamethylene biguanide hydrochloride have been provided in the form of liquid preparation. In general, liquid germicidal compositions are provided in the form of concentrated solution that is diluted upon use. However, a lot of time is required for dilution. When the concentration of the solution is incorrectly adjusted, there is a possibility that germicidal effect will not be exerted or irritation to the skin or the like will occur. Meanwhile, if a germicidal composition can be provided in the form of solid preparation, its concentration can be accurately and easily adjusted. The solid composition can contribute to the downsizing and weight reduction of products, improvements in working efficiency such as saving in storage area, the reduction of packaging materials and the lowering of transporting costs.
From the circumstances as described above, desired germicidal composition is a solid composition which has germicidal effects on fungi such as mold and on general bacteria as well as on drug-resistant microorganisms, hardly causes development of drug-resistance in microorganisms even when the composition is continually or continuously used and remains less slimy and less sticky after using the composition.